What on earth is the point of a monochrome sensor when you can get black-and-white images from a regular camera? And yet Leica and medium format maker Phase One believe that only a monochrome sensor can deliver the quality that the most ardent black and white fans demand. Why?
It’s true that any regular digital camera can produce black-and-white images either in-camera or later in a photo editor, but they come with a technical compromise. The photosites on the sensor are sensitive only to light, not color, so in order to make sensors capture color images, the makers use a CFA (color filter array) overlaid on the photosites so that each one is sensitive to red, green, or blue light only. That’s no good on its own, so it needs an interpolation process to work out a full-color value for each photosite (pixel) based on those around it. The result of this interpolation process is a slight softening of fine detail and some noise and artifacts in the individual red, green, and blue color channels that make up the color image.
